1. Field Of The Invention
This invention relates to packers and bridge plugs for use in a well bore, and more particularly, to an inflatable packer and bridge plug, along with a releasing tool therefor.
2. Brief Description Of The Prior Art
During the life of an oil or gas well, it is often desirable to perform treating operations on some subsurface zone of the well. Such operations can be very costly because they involve moving and setting up expensive equipment. For example, when workover or squeeze cementing operations are performed on an existing oil or gas well, a drilling or workover rig must be moved onto the location. Moving such equipment always involves a sizable expense to the operating company. This is especially true when a well is located in a remote area such as the North Slope of Alaska, the North Sea and the Mid East. In these locations, the expense of moving the drilling o workover rig often exceeds the value of benefits gained from the service.
Also, when squeeze cementing, treating, fracturing and other services are performed on wells, it is necessary to take the costly step of removal of production tubing from the well during the treatment. Accordingly, this high workover cost creates the need for tools which can be run on small diameter coiled tubing and which can pass through production tubing and other equipment and be set with work string pressure inside the casing. This is particularly desirable on deviated wells, but is also desirable on straight wells.
The present invention meets these needs by providing a coiled tubing set inflatable packer and a bridge plug. Also included in the invention is a releasing tool which allows the packer and bridge plug to be released and left in the well bore when necessary or desired.
A problem with prior art inflatable packers is that they might not properly set, and if this occurs in some cases, the packer must be removed and retrimmed. The inflatable packer portion of the present invention solves this problem by providing an indexing J-slot design which permits a plurality of attempts at setting the packer. On the final pressure cycle, a J-slot mandrel shifts down to open a valve in the tool.